For what does compost tea not work, tom?
I tried to look up some actual research on compost tea at one point, but the only research I found was about using it as a foliar spray to cure disease. It did not work very well for that -- but then neither does much of anything else.
Compost tea is not fertilizer. You can't add compost tea and think you have fertilized your garden. But I and a number of other people around here think that it does really help to improve soil health, release nutrients that are present in the soil, and generally give more robust, happier plants. One thing it does is make your compost go farther. Compost is really good stuff to add to your soil. On a small scale at home, it is hard to make enough compost to make much difference added directly to the soil of a few hundred square feet of garden. By culturing it in liquid you can add the benefits to a lot more of your garden. Maybe by next year I will have enough gardens built that I can try a comparison, with and without compost tea.
Will bagged compost work for compost tea? I don't know. What you are doing by brewing up the tea is culturing a bunch of the beneficial microbes in the compost. The question is if all that microbial life survives in the bagged compost. You could try it and see. What you will be looking for is if your compost tea develops foam at the top.